Signal valve device



5631.21, 1936. HEWlTT 2,028,605

SIGNAL VALVE DEVICE- Filed Jan. 13, 1933 w i p l 4 INVENTOR 4 s I ELLISE.HEWITT i ATTORNEY Patented Jan. 21, 1936 UNITED d'l'ATEE zszastsfiATEN'i OFFHQE SIGNAL vAL'vn DEVICE Application January 13, 1933,Serial No. 651,487

22 Claims.

This invention relates to signal valve devices and more particularly toa signal valve device adapted to be controlled by variations in fluidpressure.

5 The principal object of my invention is to provide an improvedpneumatically controlled signal valve device which is light in weight,simple in construction, cheap to manufacture and very sensitive tovariations in fluid pressures, and which, at the same time, is stableagainst accidental operation by unintentional fluctuations in fluidpressures.

The fluid pressure signal system employed on railway trains usuallycomprises a signal whistle and a signal valve device located on thelocomotive or head vehicle of the train, a signal pipe and a vent valvedevice on one or more cars of the train adapted to be operated by atraimnan to vent fluid under pressure from the 20 signal pipe to effectthe operation of the signal valve device to supply fluid under "pressureto the signal whistle to cause the whistle to sound a signal. Theoperating characteristics of the type of signal valve device now incommon use 25 are such that if the signal vent valve device ismaintained in venting position for a given period of time on either ashort or a long train, the duration of the signal blast from the signalwhistle will vary according to the length of the train, 30 that is tosay that the signal blast on a long train will be of shorter durationthan on a short train. The trainman of course tries to produce signalblasts of uniform duration and, in attemping to produce such signals, hemust esti- 35 mate the length of the train and approximate, as nearly aspossible, the period of time the vent valve device is to be maintainedin venting position. It will thus be seen that, since the trainman mustuse his own judgment as to the length & of the train and as to theperiod of time the vent valve device is to be maintained in ventingposition, signals of uniform duration cannot be dependably efiected.

Since it is very diflicult to effect signals of substantially uniformduration with the signal valve devices now employed, only one code ofsignals can be safely used, which code consists of one or more signalblasts regardless of the length of each blast.

Another object of my invention is to provide a pneumatically controlledsignal valve device which, when employed in a railway train signalsystem, will function, regardless of the length of the train, to causethe engineers signalwhistle to sound a signal of substantially uniformduration upon the trainman maintaining the vent valve device in ventingposition for a predetermined period of time, thus eliminating theaforementioned difficulties and making it possible to safely use a codeof signals consisting of signal blasts of varying duration which resultsin the saving of signal pipe air and makes it possible for the trainmanto transmit intelligence to the engineer in a shorter period of timethan is now required by the use of the old code.

Other objects and advantages will appear in the following more detaileddescription of the invention.

In the accompanying drawing, Fig. 1 is a cross sectional view of a.signal device embodying my invention; Fig. 2 is an enlarged detail crosssectional view of a portion of the signal device showing the particularconstruction of one 0! the valves of the device; Fig. 3 is a sectionalview taken on the line 3-3 of Fig. 1; Fig. 4 is a side elevational viewof one of the end portions of the device; and Fig. 5 is a diagrammaticview of a train signal system embodying my invention, the equipment forthe locomotive and two cars being shown.

According to the drawing, the signal valve device may comprise anannular cast metal casing section B and alsopcmprises sheet metal casingsections 2 and 3 which are clamped to the casing section I by bolts 4which pass through registering openings in the section I, an annularflange 5 of the section 2 and an inturned flange 6 oi the section 3, theinner end of each bolt having screw-threaded connection with a lug lwhich is preferably welded to the flange 5, and the head 35 of the boltengaging the outer surface of the flange 5 of thesection 2.

In the present embodiment of the invention, supporting brackets 8 arewelded to the exterior of the casing section 2, which brackets areadapted to be secured in any desired manner to a suitable supportingstructure, (not shown). Also welded to the exterior of the casingsection 2 is a lug 9 having a passage Ill formed therein which is openat one end to a passage ll in the casing section and open at the otherend to a pipe H2 which is in communication, in the usual manner, with atrain signal pipe 50 which is continuous throughout the length of thetrain.

The casing section I is provided with integral spaced arms l3, l4 and I5which merge together at the center of the section, the arm it: having apassage it formed therein which is open at one end to a pipe ll leadingto a signal whistle it, said passage being open at the other A5 end to arecess I9 formed in the central portion of the casing section. Securedto the central portion of the casing section, within the recess I9, is achoke plug 29 having a restricting passage 2I which is open at all timesto the chamber I9 and also having a seat rib 22 on which a valve 23hereinafter described, is adapted to seat.

Clamped between the casing sections I and 2 is a flexible diaphragm 24and clamped between the casing sections I and 3 is a flexible diaphragm25, said diaphragms, togethen with the casing sections defining chambers26, 21 and 28, the chamber 26 being in constant communication with thetrain signal pipe by way of passage II in the casing section 2, passageI in the lug 9 and pipe I2.

Between the flexible diaphragms' there is arranged a follower membercomprising followers 29 and 39 which are rigidly secured together inspaced relation to each other by spaced struts 3I', the follower 29.engaging one side of the flexible diaphragm 24 and the follower 39engaging one side of the flexible diaphragm 25. Contained in the chamber26 and engaging the other side. of the diaphragm 24 is a follower 32,and contained in the chamber 28 and engaging the other side of thediaphragm is a follower 33, said followers and follower member beingclamped together and to the flexible diaphragms by means of machinebolts 34 having screw-threaded connection with the fo-l lower struts 3I.This diaphragm and follower assembly constitutes a movable abutment forcontrolling the operation of certain valves as hereinafter described.

The follower 32 is provided with a central recess 35 containing thevalve 23 and also containing a spring 5I which tends to maintain thevalve seated on the seat rib 22'. This recess is in constantcommunication with the chamber 26 by way of a small port 36 in thefollower.

The follower 29 is provided with an opening 31 for the accommodation ofthe valve seat portion of the choke plug 29. This opening is of lessdiameter than that of the valve 23, so that the follower 29 operativelyengages one side of the valve. The valve 23, beyond its seating portion,is provided with perforations 38 through which the recess 35 is inconstant communication with the chamber 21 by way of the opening 31 inthe follower 29.

The follower 33 is provided with a central bore 39 containing a valve 40having a stem M which is slidably guided within the central bore 42 of afollower stem 43 having screw-threaded connection, at one end, with thefollower 33 within the bore 39, said valve being subject to the pressureof a spring 44 interposed between and engaging the valve 49 and stem 43.The follower stem 43, at its other end, is slidably guided in a guidemember 45 which is welded or otherwise secured to the casing section 3.

The valve 49 is provided with an extension 46 which is preferably roundin cross section and tapers from its greatest diameter adjacent thevalve seating surface to its lesser diameter at its end. This projectionextends through a port 41 in the follower which is normally closed bythe valve.

The chamber 28 is constantly open to the bore 39 in the follower 33 byway of a port 48 and is also constantly open to the chamber 21 through aport 49 of small diameter in the follower 33'.

Interposed between and engaging the casing section 2 and the follower 32is acoil spring 59 which is adapted to function to prevent the signalvalve device from operating to effect a signal under unintentionalfluctuations in signal pipe pressure caused by leakage of fluid from thesignal pipe or otherwise.

When the signal pipe 69 is charged with fluid under pressure in theusual manner, fluid from this pipe flows through the pipe I2, passageII! in the lug 9 and passage I I in the casing section 2 to the chamber26. From the chamber 26, fluid flows to the chamber 21 by way of port 36in the follower 32,.recess 35, perforations 38 in the valve 23 andopening 3'! in the follower 29. Fluid under pressure flows from thechamber 21 through the port 49 to the chamber 28. Thus the chambers 26,21 and 28 are charged with fluid to the pressure normally carried in thesignal pipe. It will here be noted that in charging these chambers, thediaphragms may have a tendency to flex inwardly due to the chambers 26and 21 being charged more rapidly than the chamber 28 can be chargedthrough the small port 49, but before the diaphragms can be undulyflexed in this direction; they are brought to a stop by the follower 29contacting with stops 52 carried by the arms I3, I4 and I5 of thecasingsection I.

From an inspection of Fig. 1 of the drawing it will be seen that thereis sufficient clearance space provided between the valve 23and thefollower 32, that, when the diaphragms flex inwardly, they will not actto materially increase the seating pressure of the valve on the seat 22,thus y effectively preventing the valve from being cut or unduly worn bythe seat 22. The inward flexing of the diaphragms does cause a slightadditional compression of the spring 5|, but the increase in. thepressure of the valve on its seat, due to such compression, is so slightas to be negligible.

In order to signal the engineer, a car discharge valve 91 of the usualwell known construction, is operated by a trainman tovent fluid from thesignal pipe. A reduction in fluid pressure is thus effected in chambers26 and 21 in the signal valve device and, since the pressure of fluid inthese chambers is reduced at a faster rate than fluid can flow from thechamber 28 through the small port 49 in the follower 33, the higherfluid pressure in the chamber 28 will act to deflect the diaphragms 24and 25 outwardly in unison.

The follower 29, as it is moved outwardly by the diaphragms, raises thevalve 23 from the seat 22, permitting fluid under pressure to flow fromthe chambers 26- and 2'! through the passage 2| in the choke plug 29,passage l6, pipe I1 and Whistle I8 to the atmosphere. The diaphragmscontinue to move outwardly and following the unseating of the valve 23,the tapered extension 46 of the valve 49 is moved into abuttingengagement with the arm I5 of the casing section I, so that thecontinued movement of the diaphragms causes the follower plate 33 tomove relative to the valve 49, and the seat for such valve is moved outof seating engagement with the valve. In addition to the flow of fluidthrough the small port 49, fluid now flows from the chamber 28 to theatmosphere by way of passage 48 in the follower 33, bore 39, past theopen valve 49 and its tapered extension 46, chamber 21, past theunseated valve 23, passages 2I and I6, pipe I? and whistle I8. Fluidcontinues to flow from the chamber 26 and connected signal pipe throughthe whistle l8. It will here be understood that the rate of flow offluid from the chamber 28 to the whistle when the valve 46 is open willexceed that of the flow of fluid from the chamber 26 by way of thepassage 36.

Now when the pressure of fluid in chamber 28 has been reduced by theflow of fluid to the whistle to substantially the pressure of fluid inchamber 26 or slightly below the pressure of fluid in chamber 26, thediaphragms and parts associated therewith, will be flexed inwardly totheir normal positions as shown in Fig. 1, in which the valve 23 isseated, closing off the flow of fluid to the whistle i8 and in which thefollower 33 seats on the valve 40, closing communication from thechamber 28 to the chamber 21 by way of the passage 48.

The spring 59 which is primarily for the purpose of stabilizing thevalve mechanism against accidental operation due to unintentionalfluctuations in signal pipe pressure, also functions to assist inshifting the valve mechanism to its normal position.

Since the volume of the signal pipe varies with the length of the train,the rate and amount of reduction in the pressure of fluid in the chamber26 of the signal valve device on a short train will be greater than on along train where the vent valve device 61 is maintained in ventingposition for a predetermined time.

With the signal valve devices now in common use, if the vent valvedevice were maintained in venting position for the same period of timeon a short or long train, the resulting signal blast would varyaccording to the length of the train, in other words, the longer thetrain is the shorter will be the signal blast.

According to one feature of my invention, the tapered extension 46 ofthe valve 40 so controls the rate of flow of fluid from the chamber 28to the whistle 18 according to the reduction in signal pipe pressure,that when the car vent valve is operated in the usual manner, as abovedescribed, the period of time over which the whistle sounds will beuniform regardless of the length of the train, as will readily beunderstood from the following description.

On a short train, when the car vent valve is opened and maintained openfor a predetermined period of time, the rate and amount of reduction isthe pressure of fluid in the chamber 25 will be such that the diaphragms24 and 25 will be caused to quickly flex outwardly until such flexing isstopped by the follower 30 engaging stops 53 carried by the arms l3,land 15 of the casing section I. In this position, the maximum rate offlow of fluid past the tapered extension 46 of the open valve 40 ispermitted, causing a fairly rapid reduction in the pressure of fluid inthe chamber 28 to create a suificient pressure difierential on thediaphragms to cause them to operate to effect the seating of the valve23 and the consequent closing ofi of the flow of fluid to the whistle[8.

On a long train, when the car vent valve is maintained open for the sameperiod of time that it is maintained open on a short train, due to thegreater length and volume of the signal pipe, the rate of reduction andconsequently the amount of reduc ion in the pressure of fluid in thediaphragm chamber 26 will be less than on a short train. As a result ofthis, the diaphragms will not flex outwardly to the same extent thatthey do on a short train, consequently the tapered projection 46 of thevalve 40 will retard the flow of fluid from the chamber 28 to a greaterextent than when the diaphragms are flexed to their extreme outerposition. By thus retarding the flow of fluid from the chamber 28, thevalve 23 is maintained open for a longer period of the operation of thesignal valve device so as to produce a signal blast of uniform length.

From the foregoing description it will be seen that the signal valvedevice will function to cause the signal whistle I8 to sound a signalblast of substantially uniform duration regardless of the length of atrain when the signal vent valve device is maintained open for apredetermined period of time.

While one illustrative embodiment of the invention has been described indetail, it is not my intention to limit its scope to that embodiment orotherwise than by the terms or the appended claims.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. .In a fluid pressure signal system for a train, the combination witha train signal pipe charged with fluid under pressure, of apneumatically operated signal indicating device, a valve deviceoperative to vent fluid under pressure from the signal pipe, and meansresponsive to a reduction in signal pipe pressure, upon the vent valvedevice being maintained in venting position for a predetermined periodof time, to supply fluid under pressure to the signal indicating deviceto efiect the operation of the signal indicating device to indicate asignal for a predetermined uniform period of time regardless ofvariations in the rate and amount of reduction in signal pipe pressure.

2. In a fluid pressure signal system for a train, the combination with atrain signal pipe charged with fluid under pressure, of a pneumaticallyoperated signal indicating device, a valve device operative to ventfluid under pressure from the signal pipe, and valve means operative intrains of diflerent lengths to supply fluid under pressure to saidsignal indicating device fora uniform period of time when the vent valvedevice is maintained in venting position for a predetermined period oftime.

3. In a fluid pressure signal system for a train, the combination with atrain signal pipe charged with fluid under pressure, of a pneumaticallyoperated signal indicating device, a valve device operative to ventfluid under pressure from the signal pipe, and valve means operativeupon a reduction in signal pipe pressure for supplying fluid underpressure from said chamber to the signal indicating device, and meansfor automatically regulating the rate of flow of fluid from said chamberto the signal indicating'device according to the reduction in signalpipe pressure.

5. In a fluid pressure signal system, the combination with a signalpipe, of a fluid pressure operated signal indicating device, a signalvalve device subject to the opposing pressures of the signal pipe and achamber and operated upon a reduction in signal pipe pressure forsupplying fluid under pressure to the signal indicating device, andmeans included in the signal valve device for varying the rate of flowof fluid to the signal indicating device according to the reduction insignal pipe pressure.

6. In a fluid pressure signal system, the combination with a signalpipe, of a fluid pressure operated signal indicating device, a signalvalve device subject to the opposing pressures of the signal pipe and achamber and operated upon a reduction in signal pipe pressure forsupplying fluid under pressure from said pipe and chamber to the signalindicating device, and means for varying the rate of flow of fluid fromthe chamber to the signal indicating device according to the reductionin signal pipe pressure.

' 7. In a fluid pressure signal system, the combination with a signalpipe, of a fluid pressure operated signal indicating device, a signalvalve device subject to the opposing pressures of the signal pipe and achamber and operated upon a reduction in signal pipe pressure forsupplying fluid under pressure from said pipe and chamber to the signalindicating device, and means for varying the rate of flow of fluid fromsaid chamber according to the reduction in signal pipe pressure.

8. In a fluid pressure signal system, the combination with a signalpipe, of a fluid pressure operated signal indicating device, a signalvalve device subject to the opposing pressures of the signal pipe and achamber and operated upon a reduction in signal pipe pressure forsupplying fluid under pressure from said pipe and chamber to the signalindicating device, and operated upon a reduction in the pressure in saidchamber by the flow of fluid therefrom to the signal indicating deviceto close off the flow of fluid to the signal indicating device, meansfor varying the rate of flow of fluid from the chamber according to thereduction in signal pipe pressure, and means restricting the rate offlow of fluid from the signal pipe to the signal indicating device.

9. In a fluid pressure signal system, the combination with a signalpipe, of a fluid pressure operated signal indicating device, a signalvalve device subject to the opposing pressures of the signal pipe and achamber and operated upon a reduction in signal pipe pressure forsupplying fluid under pressure from said pipe and chamber to the signalindicating device and operated upon a reduction in the pressure in saidchamber by the flow of fluid therefrom to the signal indicating deviceto close ofl the flow of fluid to the signal indicating device, meansfor varying the rate of flow of fluid from the chamber according to thereduction in signal pipe pressure, and means restricting the flow offluid from the signal pipe to the signal indicating device to a rateslower than the slowest rate of flow of fluid from the chamber to thesignal indicating device.

10. In a fluid pressure signal system, the combination with a signalpipe and a signal indicating device, of a signal valve device comprisinga valve operative to control a communication through which fluid underpressure is adapted to be supplied to the signal indicating device, amovable abutment subject to the opposing pressures of the signal pipeand a normally charged chamber for operating said valve, valve meansoperated by said abutment upon a reduction in signal pipe pressure forventing fluid under pressure from said chamber, and means associatedwith said valve means and cooperating with said abutment for varying therate of flow of fluid from said chamber.

11. In a fluid pressure signal system, the combination with a signalpipe and a signal indicating device, of a signal valve device comprisinga valve operative to control a communication through which fluid underpressure is adapted to be supplied to the signal indicating device, amovable abutment subject to the opposing pressures of the signal pipeand a normally charged chamber for operating said valve, and valve meansoperated by said abutment upon a reduction in pressure in the signalpipe for venting fluid from said chamber at a rate according to thereduction in pressure in the signal pipe.

12. In a fluid pressure signal system, the combination with a signalpipe and a signal indicating device, of a signal valve device comprisinga valve operative to control a communication through which fluid underpressure is adapted to be supplied to the signal indicating device, amovable abutment subject to the opposing pressures of the signal pipeand a normally charged chamber for operating said valve, and valve meanscarried by said abutment and operative upon a reduction in signal pipepressure for venting fluid from said chamber to the signal indicatingdevice at a rate according to the reduction in signal pipe pressure.

13. In a fluid pressure signal system, the combination with a trainsignal pipe charged with fluid under pressure and a fluid pressureoperative signal indicating device, of a signal valve device comprisinga plurality of signal controlling valve mechanisms, a movable abutmentsubject to the opposing pressures of the signal pipe and a normallycharged chamber for controlling the operation of said valve mechanismsand operated upon a reduction in signal pipe pressure for operating saidvalve mechanisms to supply fluid under pressure from the signal pipe andchamber to the signal indicating device, and means included in one ofsaid valve mechanisms for regulating the rate of flow of fluid from saidchamber to the signal indicating device according to the reduction insignal pipe pressure.

14. In a fluid pressure signal system, the combination with a trainsignal pipe charged with fluid under pressure and a fluid pressureoperative signal indicating device, of a signal valve device comprisinga plurality of signal controlling valve mechanisms, a movable abutmentsubject to the opposing pressures of the signal pipe and a normallycharged chamber for controlling theoperation or" said valve mechanismsand operated upon a reduction in signal pipe pressure for operating saidvalve mechanisms to supply fluid under pressure from the signal pipeand. chamber to the signal indicating device, means included in one ofsaid valve mechanisms for varying the rate of flow of fluid from saidchamber to the signal indicating device according to the reduction insignal pipe pressure, and means for restricting the flow of fluid fromthe signal pipe to the signal indicating device.

15. In a fluid pressure signal system, the combination with a trainsignal pipe charged with fluid under pressure and a fluid pressureoperative signal indicating device, of a signal valve device comprisinga plurality of signal controlling valve mechanisms, a movable abutmentsubject to the opposing pressures of the signal pipe and a normallycharged chamber for controlling the operation of said valve mechanismsand operated upon a reduction in signal pipe pressure for operating saidvalve mechanisms to supply fluid under pressure from the signal pipe andchamber to the signal indicating device, means included in one of saidvalve mechanisms for varying the rate of flow of fluid from said chamherto the signal indicating device according to the reduction in signalpipe pressure, and a restricted port in said abutment for governing theflow oi fluid from said signal pipe to the signal indicating device.

16. In a fluid pressure signal system, the combination with a trainsignal pipe charged with fluid under pressure and a fluid pressureoperative signal indicating device, of a signal valve de-- vicecomprising a plurality of signal controlling valve mechanisms, a movableabutment subject to the opposing pressures of the signal pipe and anormally charged chamber for controlling the operation of said valvemechanisms and oprated upon a reduction in signal pipe pressure foroperating said valve mechanisms to supply fluid under pressure from thesignal pipe and chamber to the signal indicating device, means includedin one of said valve mechanisms for varying the rate of flow of fluidfrom said chamher to the signal indicating device according to thereduction in signal pipe pressure, and means for restricting the flow offluid from the signal pipe to the signal indicating device to a slowervrate than the rate at which fluid under pressure is supplied from saidchamber to the signal indicating device.

17. A signal valve device comprising a casing having end sections and anintermediate section having a passage through which fluid under pressureis adapted to be supplied to: a signal indicating device, means securingsaid casing sections together, a flexible diaphragm clamped between eachend casing section and the intermediate casing section, means clampingsaid diaphragms together to operate in unison, and valve means carriedby the means clamping said diaphragms together adapted to cooperate withthe intermediate casing section to control the flow oi fluid to saidpassage.

18. A signal valve device comprising a casing having end sections and anintermediate section, means clamping said casing sections together, aflexible diaphragm clamped between each end casing section and theintermediate casing section, a member disposed between the diaphragmsand carried by the intermediate casing section, said member having apassage through which fluid under pressure is adapted to be supplied toa signal indicating device, and means carried by said diaphragms adaptedto cooperate with said member for controlling the supply of fluid underpressure to said passage.

19. A signal valve device comprising a casing having a passage throughwhich fluid under pressure is adapted to flow to operate a signalindicating device, a flexible diaphragm mounted in said casing, adiaphragm plate at one side of said diaphragm having a recess formedtherein, a valve seat carried by a portion of the casing, a valvemounted in said recess and normally engaging said valve seat to closesaid passage, a diaphragm plate at the other side of the diaphragmoperatively engaging one side of said valve, means clamping saiddiaphragm plates to the diaphragm, the second mentioned diaphragm platebeing adapted to move said valve to its open position upon the flexingof the diaphragm in one direction, and a spring interposed between andengaging the first mentioned diaphragm plate and valve for exerting aseating pressure on the valve when the diaphragm is flexed inwardly.

20. A signal valve device comprising a casing having a passage throughwhich fluid under pressure is adapted to flow to operate a signalindicating device, a flexible diaphragm mounted in said casing, adiaphragm plate at one side of said diaphragm having a recess formedtherein, a valve seat carried by the casing, a valve mounted in saidrecess and normally engaging said valve seat to close said passage, adiaphragm plate at the other side of the diaphragm operatively engagingone side of said valve, means clamping said diaphragm plates to thediaphragm, said diaphragm and diaphragm plates being movable inwardlyrelative to said valve and the second mentioned diaphragm plate beingadapted to move said valve to its open chamber normally charged withfluid under pressure and responsive to a reduction in signal pipepressure for effecting the operation of said signal indicating deviceand for venting fluid under pressure from said chamber, and means forvarying the rate at which fluid is vented from said chamber according tothe rate at which the signal pipe pressure is reduced.

22. In a fluid pressure signal system, the combination with a signalpipe charged with fluid under pressure, of a valve device responsive toa reduction in signal pipe pressure for effecting the operation of saidsignal indicating device, and means for conditioning said valve deviceto effect the operation of said signal indicating device for asubstantially constant period of time, regardless of the rate and amountof reduction in signal pipe pressure.

ELLIS E. HEWITT.

